Image data obtained by capturing under fluorescent lamp lighting includes flicker components generated by a power supply frequency of the fluorescent lamp. For example, a commercial power supply frequency is 50 Hz in the Kanto area of Japan, and a flicker frequency is 100 Hz because a fluorescent lamp flickers in each of half-wave rectification cycles of the same. A cycle of lighting flicker (flicker cycle) and a cycle of capturing (capturing cycle) differ from each other when capturing at, for instance, a frame rate of 60 fields per second is performed under such a lighting environment, and consequently a luminance of each of field images differs and a video signal includes flicker components.
There was a problem that compression efficiency of the video signal deteriorated when the video signal including such flicker components was coded. A conventional technique has been disclosed which removes noise components caused by flickers and suppresses the deterioration in the compression efficiency of the video signal (e.g., refer to Patent Literature 1). With the conventional technique, a signal level of the video signal is differentially corrected based on an amount of change (difference) in the signal level, so as to remove, from the signal level, the noise components caused by the flickers. This makes it possible to suppress the deterioration in the compression efficiency of the video signal, thereby suppressing deterioration in coding efficiency caused by the flickers.